[PATCH] gdb: Workaround stringop-overread warning in debuginfod-support.c on powerpc64

[Mark Wielaard <mark@klomp.org>]

Just like on s390x with g++ 11.2.1, ppc64le with g++ 11.3.1 produces a
spurious warning for stringop-overread in debuginfod_is_enabled
for url_view. Also suppress it on powerpc64.

 gdb/ChangeLog:

    * debuginfod-support.c (debuginfod_is_enabled): Use
      DIAGNOSTIC_IGNORE_STRINGOP_OVERREAD on powerpc64.
---

Found with the new fedora-ppc64le builder:
https://builder.sourceware.org/buildbot/#/builders/gdb-fedora-ppc64le

Alternatively we could just suppress this warning for any architecture.

 gdb/debuginfod-support.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/gdb/debuginfod-support.c b/gdb/debuginfod-support.c
index f2a31ea1952..6dc08fc29b6 100644
--- a/gdb/debuginfod-support.c
+++ b/gdb/debuginfod-support.c
@@ -193,15 +193,15 @@ debuginfod_is_enabled ()
 	  if (off == gdb::string_view::npos)
 	    break;
 	  url_view = url_view.substr (off);
-#if defined (__s390x__)
-	  /* g++ 11.2.1 on s390x seems convinced url_view might be of
-	     SIZE_MAX length.  And so complains because the length of
-	     an array can only be PTRDIFF_MAX.  */
+#if defined (__s390x__) || defined (__powerpc64__)
+	  /* g++ 11.2.1 on s390x and g++ 11.3.1 on ppc64le seem convinced
+	     url_view might be of SIZE_MAX length.  And so complains
+	     because the length of an array can only be PTRDIFF_MAX.  */
 	  DIAGNOSTIC_PUSH
 	  DIAGNOSTIC_IGNORE_STRINGOP_OVERREAD
 #endif
 	  off = url_view.find_first_of (' ');
-#if defined (__s390x__)
+#if defined (__s390x__) || defined (__powerpc64__)
 	  DIAGNOSTIC_POP
 #endif
 	  gdb_printf
-- 
2.30.2